/// <summary>
/// A* forward search for a plan that satisfies the given goal.
/// </summary>
/// <returns>Returns null if a plan could not be found, or a list of the
/// actions that must be performed, in order.</returns>
public static Queue <ITransition> Plan(
GoapAgent agent,
WorldGoal goal)
{
var worldState = WorldState.Borrow();
worldState[agent] = agent.GetState();
var regressiveSearchGoal = RegressiveSearchWorldGoal.Borrow(goal);
DebugUtils.Assert(worldState[agent].ContainsKey("x") &&
worldState[agent].ContainsKey("y") &&
worldState[agent].ContainsKey("z"),
"Agent's state must contain his position as 'x' and 'y' keys");
var path = AStarSearch.Search(agent, regressiveSearchGoal, worldState, true);
worldState.ReturnSelf();
GoapAction.WithContext.ReportLeaks();
State.ReportLeaks();
WorldState.ReportLeaks();
WorldGoal.ReportLeaks();
RegressiveSearchWorldGoal.ReportLeaks();
WorldEffects.ReportLeaks();
return(path);
}
public virtual WorldEffects GetEffectsOnAgent(IStateful agent)
{
var worldEffects = new WorldEffects();
if (effects.Count > 0)
{
worldEffects[agent] = effects;
}
return(worldEffects);
}
/// <summary>
/// Returns the effects that should be applied to the agent and the target
/// of the action.
/// </summary>
public virtual WorldEffects GetDependentEffects(IStateful agent, IStateful target)
{
var worldEffects = WorldEffects.Borrow();
if (effects.Count > 0)
{
worldEffects[agent] = effects;
}
if (targetEffects.Count > 0)
{
worldEffects[target] = targetEffects;
}
return(worldEffects);
}
/// <summary>
/// Regress worldGoal to before effects
/// </summary>
public RegressiveSearchWorldGoal RegressWorldGoal(WorldEffects worldEffects, bool inPlace = false)
{
var worldGoal = this;
if (!inPlace)
{
worldGoal = RegressiveSearchWorldGoal.Borrow();
foreach (var goal in this)
{
worldGoal[goal.Key] = goal.Value;
}
}
// Reverse change.
foreach (var effects in worldEffects)
{
if (worldGoal.ContainsKey(effects.Key))
{
worldGoal[effects.Key] = worldGoal[effects.Key].RegressGoal(effects.Value);
}
}
return(worldGoal);
}
/// <summary>
/// Apply the stateChange to the currentState.
/// </summary>
private static WorldState ChangeWorldState(WorldState currentWorldState, WorldEffects stateChange, bool inPlace = false)
{
// Copy state.
WorldState worldState = currentWorldState;
if (!inPlace)
{
worldState = new WorldState();
foreach (var kvp in currentWorldState)
{
worldState [kvp.Key] = kvp.Value;
}
}
// Apply change.
foreach (var change in stateChange)
{
if (!worldState.ContainsKey(change.Key))
{
worldState [change.Key] = change.Key.GetState();
}
worldState [change.Key] = ChangeState(worldState [change.Key], change.Value);
}
return(worldState);
}